2012-11-23 / In the Know

In the Know

New winter operations for public works
By Dick Collins Special contributor

With winter rapidly approaching, public works is busy preparing for winter operations.

From Nov. 15 until April 15 all staffers are on call around the clock. Upon receiving a call to report to duty they have one hour to be present and on the road. This practice has been in place for many years and the dedication of the staff is the backbone to our winter operations program.

Throughout the years there have been a number of products and procedures presented that are guaranteed to make the roads safer while saving communities money. The majority of these products and procedures have turned out to be passing fads with towns going back to tried and true methods.

The basic process to fighting a winter storm still continues to be salting the road quickly so that snow does not bond to the road surface.

After the salt is spread the next step is constant plowing of 328 lane miles so that the traveling public can safely pass to their destination. After the storm stops there is still another four to six hours of clean up that also requires additional salting to get the roads bare. These steps have been followed for years.

This year we will be adding a new product and technique to the snow fighting toolbox. Public works will now use magnesium chloride with an additive alongside the proven methods we have used for many years.

The department will pretreat mainline roads with liquid magnesium chloride. We will also be wetting the salt with magnesium chloride as it is applied to the roads.

This is a major game changer for us. By using this new approach we have flexibility we have not had in the past.

The timing of a storm is as critical as the amount of snow received when it comes to proper management of an event. If you are stuck in traffic because the storm started at 4 p.m. then our plow trucks most likely are as well.

The exciting part of pretreatment is, if we know when the storm is likely to start we can have the magnesium chloride on the road hours before.

The benefit to you as a motorist is, roads will stay clear due to the melting effect that magnesium chloride provides when sprayed on the road.

As an added benefit we no longer need to be on the road during the busy commuting time so we won’t be slowing traffic salting the roads while you are driving to or from work.

Magnesium chloride is a replacement for calcium chloride. Calcium chloride is a very corrosive product that is used as a catalyst to activate rock salt.

Salt by itself is effective as a snow melter down to a temperature of about 18 degrees.

When the temperature dips below 18 degrees, liquid calcium is sprayed on the salt to attract moisture from the atmosphere to activate the salt. On a corrosivity scale, salt is 121 while rock salt is 100.

Magnesium chloride with additive is only 11.76 on the same scale.

To put this in perspective, rainwater is 18 on the same corrosivity scale.

There are many advantages to the new product. We still need to employ old practices, but salt use is greatly reduced while road conditions are improved. In my next article I will write about the cost savings anticipated in reduced salt use and vehicle expense.

For more information or questions on this article or any public works subject, I can be reached at dcollins@ci. scarborough.me.us or 730-4400.

Dick Collins is deputy director for Scarborough Public Works.

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